1. Technical Field
The present invention relates to a method for curing thin films on substrates in general, and, in particular, to a method for thermally processing thin films on low-temperature substrates.
2. Description of Related Art
In general, thermal processing encompasses sintering, annealing, curing, drying, crystallization, polymerization, chemical reaction initiation and modulation, dopant drive-in, degasification, etc. Thermal processing of semiconductor thin films is typically performed in high temperature environments. For example, amorphous silicon (a-Si) is annealed at 1,100° C., and silicon nanoparticle films are sintered at 900° C. Thus, the high-temperature requirement for processing semiconductor thin films often mandates the usage of high-temperature substrates, such as fired ceramics or quartz, as the choice substrates for carrying semiconductor thin films.
Needless to say, it is more desirable to use low-temperature substrates, such as borosilicate or soda lime, as the choice substrates for carrying semiconductor thin films if possible because of their relatively low cost. Even more desirable substrate materials would be plastic (i.e., polycarbonate, polyimide, PET, PEN, etc.) or paper because their cost is even lower.
However, the usage of equipment that can provide an equilibrium process, such as an oven, is not a viable option for thermally processing a semiconductor thin film on a low-temperature substrate. This is because the required temperature for annealing and sintering most, if not all, semiconductor thin films are considerably higher than the maximum working temperatures of low-temperature substrates such as polyimide and PET, which are around 450° C. and 150° C., respectively.
The present disclosure provides a method for thermally processing thin films on low-temperature substrates.